Excess iron alters the fatty acid composition of chloroplast membrane and decreases the photosynthesis rate: a study in hydroponic pea seedlings

Abstract

As an essential micronutrient, iron (Fe) is directly involved in several fundamental processes in the photosynthetic cells. However, it is not clear if photosynthetic traits affected by high ferrous level are associated with changes in fatty acid composition in chloroplast membranes. To accomplish this, the effects of excess Fe 2? on the fatty acid composition and the fluidity properties of the chloroplast membrane, photosynthesis rate and the chlorophyll fluorescence were investigated in pea (Pisum sativum L.) seedlings grown hydroponically in nutrient solutions with 100, 200, 400 and 600 lM Fe 2? supplied as FeSO 4 . Increased fluidity of the chloroplast membranes was found under higher Fe 2? treatments, and this might be attributed to the increase in relative content of unsaturated fatty acids (USFA). Excess Fe 2? decreased the chlorophyll content and the electron transport rate, deactivated reaction center of photosystem II, and declined plant net photosynthetic rate. Finally, the reduced plant dry weight was observed. The results indicate that the effects of excess Fe on photosynthesis and fluidity of chloroplast membrane depend on the stress strength and duration, and the increased fluidity of chloroplast membrane may be critical in maintenance of cellular integrity under excess but not lethiferous Fe 2? treatment.

Several Pesticides Influence the Nutritional Content of Sweet Corn

“…In addition, increases in mineral element concentrations have the potential to enhance biochemical processes that impact the synthesis of many nutrients. For example, increases in Fe content in pea ( Pisum sativum L.) seedlings caused them to have more unsaturated fatty acids . The nicosulfuron plus isoxadifen-ethyl treatment in our studies displayed the highest levels of Fe content and similarly altered the ratios of fatty acids in the corn kernels, leading to increases in unsaturated fatty acids (Tables and ).…”

“…For example, increases in Fe content in pea (Pisum sativum L.) seedlings caused them to have more unsaturated fatty acids. 43 The nicosulfuron plus isoxadifen-ethyl treatment in our studies displayed the highest levels of Fe content and similarly altered the ratios of fatty acids in the corn kernels, leading to increases in unsaturated fatty acids (Tables 3 and 4). Also, deficiencies in Mg, Mn, and Fe in alfalfa (Medicage sativa L.) have led to decreases in the production of key amino acids.…”

Iron toxicity increases oxidative stress and impairs mineral accumulation and leaf gas exchange in soybean plants during hypoxia

“…Fe is an essential element for plants because it is involved in the reversible redox reactions, the biosynthesis of chlorophyll and hormones, the repair of DNA, and the protection against biotic and abiotic stresses (Connorton et al 2017;Herlihy et al 2020). However, the accumulation of Fe can be extremely toxic to plants, leading to intense oxidative stress, damage to macromolecules, inactivation of enzymes, and decreases in photosynthetic activity (de Oliveira et al 2013;Xu et al 2015;Lapaz et al 2020;dos Santos et al 2019dos Santos et al , 2020. In this study, plants supplemented with 1.8 mM Fe presented ca.…”

“…Moreover, Fe toxicity resulted from hypoxia can be further accentuated in soils containing high concentrations of Fe. In plants, Fe toxicity leads to nutritional disorders (Pan et al 2016;Maranguit et al 2017;Matin and Jalali 2017), impairs leaf gas exchange (Pereira et al 2013;Müller et al 2017;dos Santos et al 2019dos Santos et al , 2020, and increases the generation of hydroxyl radicals via the Fenton reaction, which damages various biomolecules such as lipids, proteins, pigments, and DNA (de Oliveira et al 2013;Stein et al 2014;Xu et al 2015;Das et al 2020;Lapaz et al 2020).…”

Soil Waterlogging Associated With Iron Excess Potentiates Physiological Damage to Soybean Leaves

“…The photosystems (PSI and PSII) in plants are composed of a core complex (Chl a and β-carotene) and a peripheral antenna system (Chls a and b and carotenoids) (WIENTJES et al, 2017). Under soil waterlogging and Fe excess, the content of Chl a and Chl b behaved similarly to that of Tchl (Table 3 Hence, it was assumed that both stresses degraded the chlorophylls, leading to photooxidative and oxidative damage to photosystems (XU et al, 2015), as verified by the increase in amount of MDA and H2O2 content (Figure 2a and Table 4). Consequently, the reduction of photosynthetic pigments can affect the light energy utilisation and dissipation (LAPAZ et al, 2020).…”